I wrote a book about adult ADHD last year & make ~$500/mo from it between Amazon, Audible, & Gumroad: https://adhdpro.xyz/
Recorded the audiobook myself too.
Recorded the audiobook myself too.
Also, what did you use to write your book? And how long did it take to write?
I wrote it with Microsoft Word. I initially tried a few different apps but all of the organizational tools they provided got in the way. I broke most conventions and just wrote the book straight from start to finish, and re-read it countless times until I felt satisfied. Then I sent it to a ton of friends who helped me edit. A professional editor would've been a better idea, but I didn't really have the money for that at the time.